Polymerization of vinyl acetate in aqueous media. Part I. The kinetic behavior in the absence of added stabilizing agents

Vinyl acetate has been polymerized in buffered aqueous solution at 40°C., with potassium peroxydisulfate as initiator, a dilatometric method being used to follow the reaction. Without the addition of emulsifying agents, a stable suspension of polymer particles is formed resembling a latex obtained in emulsion polymerization. It has been found that the number of latex particles after increasing in the initial stages remains constant for the major part of the reaction. The kinetics of the polymerization conform to the third case of the Smith and Ewart scheme, if it is assumed that the concentration of the monomer in the latex particles remains constant. The calculated propagation constant compares favorably with that for bulk polymerization, while the termination constant compares with that found for highly viscous systems.